package com.cll.netty.nio.groupchat;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Scanner;

public class GroupChatClient {
	
	private final String HOST = "127.0.0.1"; // 服务器ip
	private final static int PORT = 6669; // 服务器端口
	private Selector selector;
	private SocketChannel socketChannel;
	private String username;
	// 构造器，完成初始化工作
	public GroupChatClient() throws IOException{
		
		selector = Selector.open();
		// 连接服务器
		socketChannel = socketChannel.open(new InetSocketAddress("127.0.0.1", PORT));
		
		// 设置非阻塞
		socketChannel.configureBlocking(false);
		// 将channel 注册到selector
		socketChannel.register(selector, SelectionKey.OP_READ);
		// 得到username
		username = socketChannel.getLocalAddress().toString().substring(1);
		
		System.out.println(username + "is ok....");
		
		
		
	}
	
	// 向服务器发送消息
	public void sendInfo(String info) {
		
		info = username + "说：" + info;
		try {
			socketChannel.write(ByteBuffer.wrap(info.getBytes()));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	// 读取从服务器端回复的消息
	public void readInfo() {
		try {
			int readChannels = selector.select();
			if(readChannels > 0 ) { // 有可以用的通道
				Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();
				while(iterator.hasNext()) {
					SelectionKey key = iterator.next();
					// 判断是否可以读
					if(key.isReadable()) {
						// 得到相关的通道
						SocketChannel sc = (SocketChannel)key.channel();
						// 得到一个buffer
						ByteBuffer buffer = ByteBuffer.allocate(1024);
						// 读取
						sc.read(buffer);
						// 把读到的缓冲区的数据转成字符串
						String msg = new String(buffer.array());
						System.out.println(msg.trim());
					}
					
				}
				iterator.remove(); // 删除当前selectionKey，防止重复操作
			}else {
				//System.out.println("没有可以用的通道。。。");
			}
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
	}
	
	public static void main(String[] args) throws Exception {
		// 启动客户端
		final GroupChatClient chatClient = new GroupChatClient();
		
		// 启动一个线程，每隔3秒读取从服务器发送数据
		new Thread() {
			public void run() {
				while(true) {
					chatClient.readInfo();
					try {
						Thread.currentThread().sleep(3000);// 休眠3秒
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
			}
		}.start();
		
		Scanner scanner = new Scanner(System.in);
		while (scanner.hasNextLine()) {
			String s = scanner.nextLine();
			chatClient.sendInfo(s);
			
		}
	}
	

}
